The disclosure concerns a method for operating a braking device of a vehicle, in particular a parking brake device, wherein the braking device comprises an electromotive actuator that displaces an actuator element either into a clamping position for subjecting a brake disk to a clamping force or into a release position for releasing the brake disk, wherein a brake disk temperature is determined in order to activate the actuator depending on the determined brake disk temperature.
The disclosure further concerns an apparatus for performing the method as well as a braking device with such an apparatus.
A method, apparatuses and braking devices of the aforementioned type are known from the prior art. Automatic parking brake systems, in particular of the “motor-on-caliper” type, are generally used on rear wheel brakes of motor vehicles in order to lock the wheels of the rear wheel axle when the vehicle is stationary. For this purpose an electromotive actuator is provided that drives or displaces an actuator element in order to subject a brake disk to a clamping force in a clamping position of the actuator element and to release the brake disk in a release position of the actuator element. Present-day braking devices have the disadvantage that a loss of clamping force can occur if the braking device cools after the time of parking. Here the loss of clamping force is higher, the higher is the temperature difference between the time of parking and a cooled final state. A brake disk temperature model that determines the temperature of the brake disk during driving operation is increasingly available for braking devices, and as a result activates the electromotive actuator depending on the determined brake disk temperature so as to be able to adjust a clamping force that takes into account the loss of clamping force. Present-day brake disk temperature models are however relatively inaccurate, because they are also influenced by many environmental variables, such as temperature, weather, rim material and shape, wheel covering, wheel size, attachments and similar. In order to increase the accuracy, nowadays the temporal behavior of the wheel pressures and the speed are essentially taken into account.